This invention relates to ink jet printers. More particularly, it relates to continuous jet ink jet printers, which are used for marking alpha-numeric characters and the like on substrates. Typically, these commercial printers are used for applying date codes, place of manufacture codes and related information on products as they are manufactured. Such printers must be versatile, working in fairly hostile industrial environments, and quite reliable as down time is particularly unwelcome as it affects the output of the factory. Such ink jet printers are typically housed in a cabinet at a location some distance removed from the actual site of the printing. A printhead is connected to the printing cabinet by an umbilical duct which carries ink to and from the printhead as well as the electrical signals required to operate the printhead.
When installing a new printer or when servicing the printhead, it is necessary to prime the printer, that is to fill the ink supply line with ink and to remove as much, if not all, of the trapped air as possible. Failure properly to prime and remove air is a major cause of misprinting. Because of the use of the umbilical this priming process and the related purging and cleaning operations can be quite time consuming and presently require substantial manual intervention by a skilled technician as described hereafter. Obviously, the elimination or reduction of this downtime and the requirement for skilled, manual servicing are desirable goals. It is accordingly an object of the present invention to reduce the time and frequency of operator intervention to set up an ink jet printer.
It is a further object of the invention to provide an automated system for self-priming which will remove substantially all of the air entrapped in the ink supply line, valves and nozzles associated with the printhead.
It is a further object of the invention to provide an automated system for priming of an ink jet printer and purging of air.
Another object of the invention is to provide a safer and more efficient method for recovering the fluids used during the cleaning and priming operations. These and other objects of the invention will be apparent from the remaining portion of the specification.